JPS6323676A - High frequency heating method and apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating method and apparatus for heating a living body using electromagnetic waves.

The method of heating a living body using electromagnetic waves utilizes the heat generation phenomenon that occurs when electromagnetic waves incident on a living body are absorbed by various parts of the living body, and many reports have been made in recent years regarding its effectiveness in treating malignant tumors.

In the conventional high-frequency heating method, for example, as shown in FIGS. 1 and 2, a region 3 including a target heating region 2 of a living body 1 is sandwiched between two opposing plate electrodes 4 and 5, and a high-frequency power source 6 is used. Thermotherapy was performed by passing a high frequency current between these electrodes.

In this method, since the high-frequency current flows almost parallel in the area between the opposing electrodes, there is a risk that areas other than the target heating area 2 may receive similar heating, and that the subcutaneous fat layer I and the lumen fi II organ tissue The subcutaneous fat layer 7 tends to be heated more strongly due to the difference in electrical constants (conductivity, permittivity) between the Complaint 1: Due to the risk of superficial tissue burns, it was difficult to heat the deep target heating region 2 to the treatment temperature.

To address the above problem, as shown in FIGS. 3 and 4, the device is surrounded by a flexible, airtight bag-like body made of silicone rubber, etc., and has a mechanism for supplying and discharging cold moon 1 liquid into the bag-like body. 1st electrode rest 4
and the second electrode body 5, the first electrode body (warming electrode body)
A second electrode body (insensitive electrode body) having an electrode area several times or more larger than the first electrode body is placed near the target heating site, and a second electrode body (insensitive electrode body) is placed on the outer periphery of the living body, and a high-frequency current is passed between them. , a strong electric field distribution is created in the vicinity of the first electrode body to selectively heat the target heating area, and a
A method has been proposed for monitoring the surface temperature of a living body or controlling the high-frequency generation output based on information from a temperature sensor.

However, in the above method, when water is used as the cooling liquid, the refrigerant temperature or the introduced amount 'S
This may affect the temperature sensor's readings, resulting in more heating or cooling than necessary, and there is no guarantee that the affected area is being heated effectively.

Therefore, there is a current need for the development of a method and device that can warm the affected area under quantitative control without causing any heat sensation or pain to the patient when heating the body using electromagnetic waves.

The present invention has been made in view of the above-mentioned current situation, and its purpose is to eliminate the patient's sensation of heat and pain using information from a temperature sensor located on the outer surface of the electrode body. An object of the present invention is to provide a heating method and device that can perform effective heating treatment.

According to the present invention, this purpose is achieved by using a VV which is surrounded by a flexible and airtight bag-like body and which supplies and discharges a cooling liquid into the bag-like body.
a first electrode body having an S structure and configured to be placed near the target heating site; and a large 518 or more electrode body configured to be placed on the outer circumference of the living body By passing a high-frequency current between the second electrode body and the second electrode body, which has an electrode area, a stronger electric field distribution is created near the first electrode body, and the target heating area around the first electrode body is selectively heated. Heating - 〇 - In the device, a refrigerant having physical properties similar to those of the biological tissue at the electrode body installation site is used as the cold liquid, and the first electrode body side is heated at a rate of 1 per minute with respect to the internal volume of the bag-shaped body. 1 from double the amount
This is achieved by circulating five times as much of the cooling fluid.

Next, the present invention will be explained in detail.

The second electrode body (insensitive electrode body) in the present invention is, for example, an electrode body as disclosed in Japanese Patent Application Laid-open No. 60-55966 (see below). It has an electrode area that is usually 5 times larger, preferably 100 times larger than that of the first electrode body, and has a significantly small heating effect on the living body when working in cooperation with the first electrode body. The first electrode body (heating electrode body) is used for the target heating site, such as the esophagus, stomach, l! This electrode is large enough to be placed inside a living body cavity or on the surface of an affected area of the breast, and by passing high-frequency electricity between it and the second electrode body, a strong electric field distribution is created in the vicinity of the second electrode body to target the desired body tissue. can be selectively heated.

The physical characteristics of the biological tissue to be humidified and the cooling liquid that approximates it will be explained as follows.

That is, when a material with a dielectric constant ε and a loss power factor tan δ is placed between a pair of electrodes and a high frequency voltage of frequency f is applied, the power P (W) absorbed per unit volume of the material is equal to the electric field strength in the material. If the power is E and the constant of proportionality is K, then P=-f-E
It is expressed as εtanδ(W) (1).

Now, when a high-frequency voltage is applied between a small-area heating electrode (internal cavity electrode) and a large-area insensitive electrode (extracorporeal electrode), the electric field strength will be large around the small-area heating electrode. The Q decreases as the distance moves away, but the method of attenuation varies depending on the shape and configuration of the electrodes and the physical properties of the material between the electrodes, so it cannot be generally specified, but if these are known, it can be calculated. is possible.

The dielectric constant of the biological tissue outside the membrane that makes up the bag is ε
1. The loss power factor is tanδ■, and the electric field strength in this vicinity is E
, then the power PT absorbed here is expressed as PT-KfEl ε■tanδ■.

On the other hand, if the electric field strength in the refrigerant is Ec1, the permittivity is εc1, and the loss power factor is tanδC1, then the power absorbed by the refrigerant P
C is P = − f − E ε tan δ. It is expressed as

CCC Dielectric constant ε of refrigerant. , by appropriately selecting the loss rate tan δC, it is possible to make the power PT absorbed by the living tissue near the heating electrode substantially equal to the power PC absorbed by the coolant.

Therefore, the cooling fluid according to the present invention means a cooling fluid that absorbs approximately the same amount of power as the living tissue at the heating electrode installation site.

The concentration of the cooling liquid varies depending on the target biological tissue, but the concentration is, for example, 30m moff when using an inorganic salt such as potassium chloride or chloride.
/II ~160n+mofl/j, preferably 1
20mmoρ/ρ or less, or 15m for inorganic salts such as calcium chloride, sodium carbonate, potassium carbonate, sodium sulfate, potassium sulfate, etc. moff 71-80+n
An example of an aqueous solution of about WAOρ/1 will be explained. If necessary, antibiotics and preservatives may be added to the cooling liquid of the present invention. Further, No 11j32 may be Type A or a mixture of two or more types.

Next, the heating electrode is inserted into the bag-like body as described above. The introduction and circulation of IL solution will be explained.

That is, the electric power P absorbed by the tissue shown in the above equation (1) is converted into heat J energy (Q,) of Samurai x Pt per unit volume time, and a part of it, QaCal, is diffused into the surrounding area by blood flow, conduction, etc. As a result, the temperature TR of △T is brought to the tissue -0 The relationship between this is Q, -Q, = ρ・C△T ■ρ: Living tissue density C: Specific heat Density of the refrigerant (ρ), Specific heat (C ) is selected to be equal to that of living tissue, and if the heat corresponding to Q is removed by circulating the refrigerant, the temperature of the refrigerant can be increased to 8 T°C.

The amount of heat (Q) can be removed by introducing the cooling liquid of the present invention into the pouch-like body, and then using the circulating needle to reduce the blood flow rate of the living tissue, although this differs depending on the type of living tissue at the electrode installation site or its temperature state. This is achieved by making it substantially equal to IV? Ru. For example, in the case of muscle tissue, the blood flow rate of living tissue is about 2 d/min per 1 cd of tissue at a temperature of 37°C, and about 1rd per cd at a temperature of 40°C.
The cooling liquid of the present invention at a temperature of usually 15° C. to 43° C., preferably 37° C. to 43° C. is applied in an amount of 1 to 15 times the inner volume of the bag-like body per minute, although it depends on the temperature and temperature. The blood flow rate of the living tissue can be approximated by introducing and circulating the blood flow. Note that the internal volume of the bag-like body means the internal volume of the bag-like body when expanded or expanded by the cooling liquid. Since heating of the living tissue is not substantially observed on the insensitive electrode side, there are no particular limitations on the cooling fluid circulation field or its temperature.

In the device of the present invention, for example, the intracavity electrode device disclosed in JP-A-60-119962 is used as the first electrode body, and the medical electrode device disclosed in JP-A-60-55966 is used as the second electrode body. This is a high-frequency heating device that uses a refrigerant that has physical properties similar to the biological tissue at the site where the electrode body is installed as a cooling liquid of the means for supplying and discharging the cooling liquid into the bag-shaped body. This can be obtained by configuring the supply/discharge means to circulate the cooling liquid in an amount of 1 to 15 times the internal volume of the bag-like body through the bag-like body per minute.

= 12- Next, preferred specific examples of the first electrode body and the second electrode body of the device of the present invention will be explained with reference to the drawings.

5 to 7 show details of the first electrode body 4. FIG.

In FIGS. 5 to 7, reference numeral 8 denotes a flexible two-channel pipe made of silicone rubber in which a cooling liquid supply path 9 and a cooling liquid discharge path 10 are integrally formed.

A flexible high-frequency electrode 11 and a flexible bag-like body 12 having dimensions that can contact the inner wall of the hollow organ without stretching are attached to the distal end side of the tube 8. tube 8
A cooling liquid feeding connector 13 and a cooling liquid discharge connector 14 are provided integrally with the cooling liquid feeding path 9 and the D1 outlet path 10, respectively, at the base side end of the cooling liquid. Connector 13.1
4 and the pipe 8 are hardened with silicone adhesive.
Furthermore, it is covered with a heat-shrinkable duplex 8a made of silicone.

The high-frequency electrode 11 is fixed to the outer periphery of the tube 8 and excites the metal wire, but other materials such as a bellows or a spiral coil may be used as long as it has flexibility.

The length of the electrode 11 in the axial direction is formed to be as good as the length of the tumor lesion.

A tip 16 of a high-frequency lead wire 15 (for example, outer diameter of about 1 -) is fixedly connected to the base end of the high-frequency electrode 11 . This lead wire 15 extends along the outer periphery of the two-channel tube 8 to near the base of the tube 8, and a connector 17 for connection to the power source 7 is connected to the extended end.

The bag-like body 12 is formed into a cylindrical shape according to the size and shape of the lumen near the lesion to which it is applied, and if desired, the size and shape of the stenosis caused by the tumor. It is fixed to the outer periphery of the tube 8 at both ends 18, 19 which are circumferentially reduced in diameter.

When the first electrode body 4 is applied to the esophagus, the bag-like body 12 has an outer diameter of 5 to 25 s and a length of 30 to 30 s, for example.
A material with a thickness of about 100 tm is used. When the first electrode body 4 is inserted into the cavity, the bag-like body 12 is deflated as shown in FIG. 7, and preferably folded, for example, as shown by the imaginary line in FIG.

The bag-like body 12 is preferably a molded tube or balloon made of silicone rubber.

22a, 23a, 24a, 25a, 26a are copper/constantan thermocouples 22.23.24 as temperature detection means.
．． The hot junction of 25.26 is the point, and the thermocouples 22, 23
, 24, 25, and 26 are adhesively fixed to the outer surface of the bag-like body 12 so that they can be brought into close contact with the vaginal wall when the bag-like body 12 is expanded by the cooling fluid.

Lead wires 22b of thermocouples 22, 23, 24, 25, 26
, 2311.24b.

25b and 26b are fixed to the outer periphery of the central part of the tube 8 together with the lead wire 15 and the proximal end 18 of the bag-like body 12 by a silicone heat shrink tube 27 without actually intersecting the high-frequency lead wire 15. ing.

28 are the lead wires of the thermal lightning pair 221), 23b, 24b, 2
5b and 26b, and the connector 28 and the lead wire 22b.

A 10-pin socket part 30 in which 23b, 24b, 25b, and 26b are fixedly connected and the lid part is crimped.
and a lead wire 31 which is detachable from a part 30 of the socket 1 firmly shielded on the outer periphery of the tube 8 and is connected to a temperature measuring voltmeter.
It consists of a 10-pin type plug part 32 having a.

33 is a coolant discharge hole communicating with the coolant discharge path 10 of the pipe 8; 34 is a connector of a coolant supply pipe 1-b which is equipped with a pump 35 and temperature control means and connected to an IC cooler 36; The connector 34 is configured to be detachably attached to the connector 13. 37 is a connector configured to be removably attached to the connector 14 and configured to drain the coolant via the coolant discharge pipe 38 or return it to the cooler 36.

8 and 9 show the second electrode body 5 of the present invention. 8th
In the figures and FIG. 9, reference numeral 43 denotes a base made of nylon cloth coated with silicone resin. 44 is an electrode made of a copper foil plate, 45 is a stretchable silicone rubber sheet, 46 is a lead wire connected to one end of a high frequency power source (not shown), and 47 is a silicone pipe as a water supply and drainage pipe for the cooling liquid 48. be.

A portion or region 49 indicated by broken lines is a portion where the base 43 and the rubber sheath 45 are joined to form a one-way coolant flow path 50 between the tubes 47 and 47.

FIG. 9 shows IX in FIG. 8 with the coolant 48 being supplied.
This is a sectional view taken along the -IX line, and the upper side in FIG. 9 is the side brought into close contact with the living body surface. In the above, the bag-like body 4
5a is formed by a sheet 45, a base 43, etc.

This second electrode hole 5 is connected to a fixture and a silicone rubber sheet 4.
Due to the interaction with the expansion of No. 5, it can be closely attached to the living body.

When the high-frequency heating device of the present invention heats the central part, the temperature difference between the cooling liquid inside the bag-like body of the first electrode body and the biological tissue in contact with the outer surface of the bag-like body is substantially eliminated. For this reason,
According to the present invention, the biological tissue temperature can be faithfully monitored based on the instructions from the temperature sensor located on the outer surface of the bag-like body of the first electrode body regardless of the magnitude of the high-frequency output, and the temperature can be safely monitored. The target heating area can be treated with care.

Hereinafter, the present invention will be explained in detail with reference to Examples.

[Example I Diameter 15NRφ, length 80. A silicone rubber bag-like body surrounds a helical electrode with a diameter of 8 circles φ.Temperature sensor A1 is fixed to the outer surface of the center of the bag-like body of the inner cavity electrode, and temperature sensor B is fixed to the inner surface of the tube with adhesive. and inserted into the esophagus.

On the other hand, an extracorporeal electrode having a coolant flow path provided on a copper plate-L measuring 120 m x 430 m in length was attached to the chest facing the esophagus.

A saline solution of 70 mmo/fl was used as a cooling liquid, the temperature was controlled to 37° C. by inserting a lumen electrode, and the circulation flow Iq was set to 5 o−/n+tn. Since the volume V occupied by the coolant inside the bag-like body was approximately 10 m1, the circulating flow rate per internal volume was Q/V=5 times/min.

A high frequency current of 13.5 MH2 was passed between the internal cavity electrode and the external electrode at outputs of 100 W and 150 W, but as shown in Figures 10 and 11, the temperature difference indicated by sensors A and 8 was 0. It was within .5°C.

For comparison, Figures 12 and 13 show the temperature measurement results of sensor A and sensor 8 when distilled water was used as the coolant under the same conditions as in Section 1. Note that the mark O in the figure is the temperature indicated by the A sensor, and the mark is the temperature indicated by the B sensor.

It can be seen that in the case of the comparative example in which distilled water was used as the coolant, the temperature difference between the A sensor and the 8 sensor was significantly larger than that in the example of the present invention.

[Brief explanation of drawings]

Figures 1 and 2 are conceptual explanatory diagrams of the high-frequency heating method;
The figure is a schematic explanatory view of a preferable example of the shell body of the device of the present invention, FIG. 4 is an explanatory cross-sectional view taken along the line IV-IV of FIG. 3, FIG. 5 is a detailed explanatory view of the first electrode body of FIG. 3, and FIG. is Vl − in FIG.
-Vl line sectional explanatory view, Fig. 7 is a Vl - Vl line sectional view of Fig. 5 when the bag-like body is deflated, Fig. 8 is an explanatory view of the first electrode body of Fig. 3, and Fig. 9a is an explanatory view of the first electrode body in Fig. 3. [X-IX in Figure 8
10 and 11 are diagrams showing the time-temperature indication relationship in the embodiment of the present invention, and Figures 12 and 13 are diagrams showing the time-temperature indication relationship in the comparative example. It is a diagram. 1... Living body, 2... Target heating site,
3...[]Region including the targeted heating site, 4...
...First electrode body, 5...Second electrode body, 9...
... Cooling liquid supply path, 10 ... Cooling liquid discharge path, 11 ... High frequency electrode, 12 ... Bag-shaped body, 22, 23, 24, 25.26...Thermal lightning pair, 44...High frequency electrode, 45...
Sheet, 48...Liquid 741 Liquid, 49...
・Joint part. Agent Yoshio Kuchi Patent attorney Patent attorney Itaru Nakamura Figure 1 Figure 2

Claims (5)

[Claims] (1) The first part is surrounded by a flexible and airtight bag-like body, has a mechanism for supplying and discharging a cooling liquid into the bag-like body, and is arranged in the vicinity of the target heating area. an electrode body; and 5 of the first electrode body configured to be placed on the outer periphery of the living body.
By passing a high-frequency current between the second electrode body, which has an electrode area more than twice as large, a stronger electric field distribution is created near the first electrode body, and the target heating area around the first electrode body is selectively heated. In the high-frequency heating device, a refrigerant having physical properties similar to those of the biological tissue at the site where the electrode body is installed is used as the cooling liquid, and the temperature is increased per minute to the inner volume of the bag-like body on the first electrode body side. A high-frequency heating method characterized by circulating 15 times the amount of the cooling liquid. (2) Coolant is 15 mmol/l to 160 mmol/l
2. The high-frequency heating method according to claim 1, wherein the inorganic salt aqueous solution has a concentration of 1. (3) The high-frequency heating method according to claim 1 or 2, wherein the temperature of the introduced cooling liquid is 15°C to 43°C. (4) A second tube configured to be placed near the target heating site, surrounded by a flexible, airtight bag-like body, and equipped with a mechanism for supplying and discharging a cooling liquid into the bag-like body. one electrode body;
It is arranged on the outer periphery of the living body and is configured to selectively heat a target heating region around the first electrode body in cooperation with the first electrode body, and is five times the electrode area of the first electrode body. a second electrode body comprising an electrode having the above electrode area, a flexible, airtight bag-like body surrounding the electrode, and a mechanism for supplying and discharging a cooling liquid into the bag-like body; It consists of a high frequency power supply connected to the electrode body and the second electrode body to supply current to these electrode bodies, and a temperature control means for the cooling liquid, and the cooling liquid approximates the living tissue at the site where the electrode body is installed. A high-frequency heating device that uses a refrigerant having physical characteristics and circulates the cooling liquid in an amount of 1 to 15 times the internal volume of the bag-like body through the first electrode body per minute. (5) Coolant is 15 mmol/l to 160 mmol/
5. The high-frequency heating device according to claim 4, wherein the inorganic salt aqueous solution has a concentration of 1.